System of electric railway-signals.



No. 7|2,|sa. Patented oef. 2s, |902. E. P. Jessup.

.SYSTEM 0F ELECTRIC RAILWAY SIGNALS.

(Application filed Mar. 15, 1902.)

(No Model.)

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TN: Nnnms PTERS co, mom-ums., WASHINGTON, u, c.

llNiTED STATES i .PATENT GFFICE;

EARL P. JESSOP, OF THE UNITED STATES NAVY.

SYSTEM OF ELECTRIC RAILWAY-SIGNALS.

SPECIFICATION forming part of Letters Patent No. 712,138, dated October28, 1902.

` Application filed March 15, 1902. Serial No. 98,331. (No model.)

To all whom it may concern:

Be it known that l, EARL P. JEssoP, ofthe United States Navy, a citizenof the United States, have invented certain new and useful Improvementsin a System of Electric Railway-Signals 5 and I do declare that thefollowing is a full, clear, and exact description of the invention,which will enable others skilled in Vthe art to which it appertains tomake and use the same.

This invention relates to a system of electric signals for double-trackrailways; and it consists of a double conductor divided into suitablelengths to form blocks, with a source of electrical energy for one ofthe conductors in each blockforming a circuit-embracing means foractuating the air-brake system of the train and operating a signal, thesaid means `being controlled by a short circuit caused by the presenceof an engine in the next block ahead. For the purpose of my inventionone or both of the rails are grounded, and between the two is arranged apair of insulated conductors, each pair being of a suitable length toform a block. Both conductors of each pair are interrupted at the samepoint. One of them is connected at its forward end witha suitable sourceof electrical energy and atits rear end with the conductor in the blocknext behind on the other side. Each locomotive is provided with twotrolleys thereon insulated from each other, which are arranged to engagewith the two conductors between the rails. The two trolleys connect witha circuit in the cab for actuating a magnet, while one ofthem, isgrounded, preferf ably by being connected Awith one 'of the axles of thelocomotive. The armature of the magnet in the cab controls a switch inan independent circuit which includes a signal. This armature also`serves to operate a ,relief` valve in the air-brake system. Thecab-circuit is arranged to be broken and the valve t0 be closed when acircuit flows through the magnet; but upon the latter becomingdeenergized, either by a break inthe circuit or by a short circuit, thesignal will be operated and the valve opened by means of the movement ofthe armature. The arrangement of the circuitsthrough the conductors issuch that a current passes through the magnet on the locomotive when thelatter is over the second section of a conductor by means of theinsulated trolley, the l uninsulated one serving to ground the sectionthat it is in contact with. lf the block ahead of the locomotive isclear, the current from the battery therein will pass over its sectionof conductor to the section of conductor on the other side under thelocomotive, passing up the insulated trolley to energize the magnet, andwill be grounded through the other trolley. If the preceding blockshould be occupied by another locomotive, the current from the batteryin that block will be short-eircuited through the grounded trolley withwhich the conductor engages, which will have the effect of denergizingthe magnet and by the action of the spring-actuated armature Will openthe air-brake valve and move the switch to operate the signal.

The invention also relates to details of construction of theswitch-actuating mechanism for the signal and to the air-valve and itsactuating mechanism. This mechanism is as follows: A single magnet movesa lever which carries onearm of the switch in the cab signal-.circuitand also carries the movable portion of a pilot-valve, which latterserves to open and close the main relief-valve. A pilot- Valve isemployed, as the power of the magnet is necessarily limited and wouldnot be snfiicient to open or close a relief-valve against the usualair-pressure. VThe pilot-valve is combined with the relief-valve and isadapted to vary the direction of flow of a portion of the air from thetrain-pipe to actuate a piston whichopens or closes the air-reliefvalve.

The invention further relates to improvements in the particular form oftrolley adapted to be used with and forming a part of my device, soconstructed that the two trolleywheels may bear equally upon the twoconductors, even if the4 latter be not both on the same horizontalplane.

In order to better understand the nature of my said invention, attentionis called tothe accompanying drawings, forming a part of thisspecification, and in which- Figure 1 represents a diagrammaticview ofmy invention. Fig. 2 is a side view, partly in section, of the switchand air-relief valve; and Fig. 3 is a view of one form of a doubletrolley.

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In all the several views like parts are designated by identicalcharacters of reference.

In Fig. 1 the numerals 1 1 represent the rails of a system upon whichtraffic always travels from the left to right-that is, in the directionindicated by the arrow. As shown in the drawings, the track 1 isgrounded at 1"; but the other rail as well may be grounded, if desired.The double parallel conductors about to be described are preferably arranged between the two rails and are each of a length suitable to form ablock, the ends of each pair being interrupted at the same point. Theyare suitably insulated. The conductors on the left side are indicated bythe numerals 2 2'2", dac., and on the right side by the numerals 3 3'3", &c. A suitable source of electricity for each block-as, forinstance, a battery (shown at 4 4' 4)-has one pole grounded at 5 5 5"and the other connected to the forward edge 6 6 6 of the lefthandconductors 2 2 2". The rear ends of the left-hand conductors 2 2' 2,&:c., are connected at 7 7 7l to the forward ends of the righthandconductors 3 3 3". All the conductors are otherwise insulated.

The locomotive equipments represented by the letters A, B, and C areidentical, and for convenience of reference but one will be described.

Upon a portion of the running-gear of a locomotive-as, for instance, theaxle S-are secured the two trolleys 9 and 10 or a double trolley, to belater described. The two trolleys connect with a circuit 11, in which isincluded a magnet 12. The trolley 10, which engages with the right-handconductor, is carefully insulated; but the trolley 9, which engages withthe left-hand conductor, is connected at 13 to a portion of theengine-frame or to the axle8, thus forming a ground through the rail 1.The magnet 12 actuates an arxna ture-lever 14 and moves it against thetension of a spring 22. An air-relief valve 15 and a switch 16 are bothconnected to and actuated by this lever. The switch 16 is embraced in acircuit 17, which includes a battery 18 or other source of electricityand a signal 19, a lamp being shown. The switch 16 is arranged to beopen and the circuit 17 interrupted as long as the magnet 12 isenergized. As soon as this magnet becomes denergized in the manner aboutto be described the free end of the lever 14 will be depressed by theaction of the spring 22, which action will open the valve 15 to applythe brakes and also close the switch 16 to operate the signal 19.

As shown in Fig. 1, the locomotive indicated by the letter A is upon ablock, preceding which is another block, which is clear. 1 The currentfrom the battery 4 will pass along the conductor 2, up the trolley 9,and be grounded at 13, having no effect upon the magnet 12. The currentfrom the battery 4 after passing over the conductors 2 and 3 will passup the trolley 10, through the circuit 11, and will be grounded at 13,thus energizing the magnet 12 and moving the lever 14 to the positionindicated, which will have the effect of interrupting the circuit 17 andclosing the valve 15, thus indicating that the line is clear ahead.

If the locomotive be upon a block, as at B, with the block ahead closedby the locomotive C a change will occur in the circuits and in theposition of the signaling apparatus. The current from the battery 4 willbe short-circuited at 13(I on the locomotive C and will pass from theleft-hand conductor 2" to Athe rail 1 and be grounded. This willshort-circuit the battery 4 and will denergize the magnet 12 on thelocomotive B, moving the lever 14 by the action of the spring 22 awayfrom the magnet, closing the switch 16', and opening the valve 15. Theaction of closing the switch will complete the circuit 17 and actuatethe signal 19. At the same time the opening of the valve 15 will applythe brakes and stop the train.

It will be understood that the magnets are energized only so long as thecircuits are complete and the mechanism is in running order. If eitherone of the conductors should become grounded or anything shouldinterrupt the current from any battery, the magnets will becomedenergized and the signal actuated.

The particular switch and relief valve which form a part of thisinvention illustrated in Fig. 2 are constructed as follows: The base 2Ocarries a standard or support 21, upon which is pivoted the lever 14. Toone side of the standard 21 is arranged the magnet 12, and on the otherside is the relief-valve 15, the latter carrying the switch 16. A spring22 is used to draw away the lever 14 from the magnet and close theswitch 16. A screw 23 is used to adjust the tension of the spring 22.The switch consists of the contacts 24 and 25, secured to the lever 14and the valve-casing 28, respectively. 26 and 27 are bindingposts, towhich the wires forming the circuit 17 17 are secured. The operation ofthe switch is obvious, as it is of a principle well known in the art.

The relief-valve 15 consists of a cylindrical casing 28, to which thetrain-pipe 29 or a branch therefrom is connected by a port 30. Anexhaust-port 3l is located below the port 30. The port 30 vis normallydesigned to be closed by means of a piston-valve 32, connected to apiston 33 by a rod or stem 34. This piston 33 and valve 32 are adaptedto be moved by means of air taken from the trainpipe and admitted eitherabove the valve 32 or below the piston 33 by means of a pilot-valve 35.The pilot-valve embraces a stem or piston 36, connected by a rod 37 tothe lever 14, a joint 38 being provided to allow for the slightinequalityof motion which necessarily results. The valves39 and 40,carried upon the pistonrod 36, are on both sides of a port 41, to whichair from the train-pipe 29 passes by means of a pipe 42. A port 43serves as a means of com- IOO IIO

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in unication from the valve 35 to the upper part of the cylinder 28,while another port 44 connects the valve 35 with the lower part of thecylinder 28. 59 and 60 are exhaust-ports for the pilot-valve chest.

The operation of the valve is as follows: As shown in the drawings, theport 30 is closed by the Valve 32, which is depressed by the pressure ofthe air from the port 43, which is opened by the valve 39. The valve 40closes the port 44. An uninterrupted column of air from the train-pipe29 therefore passes through the pipe 42, port 41, through the port 43,and presses upon the valve 32. If the Valves 39 and 40 be now lowered bythe action of the spring 22, the valve 40 will open the port 44, thusallowing the train-air to pass from the valve 35 through the port 44 tothe lower part of the cylinder 28,engaging against the piston 33 andelevating it andthe valve 32, thus opening communication between theports 30 and 31. This action will allow free circulation of air from thetrain-pipe and will quickly reduce the pressure therein and apply thebrakes.

It will be noted that the air-pressure from the port 41 bears equallyupon the valves 39 and 40, thus balancing them and reducing the effortrequired to move them. Furthermore, the ports 43 and 44 can be made verynarrow, a construction that requires but a Very slight movement of thevalves 39 and 40. This will be an advantage by permitting a reduction ofthe size of the magnets and the batteries.

As shown in Fig. 3, a double trolley that I have designed for use inconnection with this apparatus is composed of an arm 45, to which ispivoted a yoke 46 by means of a pin or bolt 47. This yoke carries upon ashaft 48 the two insulated grooved trolley-wheels 49 and 50, adapted toengage with the left and righi; conductors, respectively. Electricalconnection is made with the trolleys. by means of the brushes 5l and 52in the well-known manner, which connect with the wires 53 and 54, theformer being grounded at 13 to a portion of the frame 55 of thelocomotive, the other wire, 54, being carefully insulated. To these twowires is connected the circuit l1, before described. The opening in theframe 55, through which the arm 45 passes, is suiciently large to allowit some lateral movement to accommodate itself to the changes inrelative position of the locomotive and conductors, as must occur inpractice. An enlargement 56 will serve to support the arm whendepressed, while a spring 57, located between the frame 55 and shoulder58 on the arm, will serve to keep the trolley-wheels always in closeengagement with the conductors. If the conductors should not be on thesame horizontal plane, the yoke 46 mayturn upon the pin 47 toaccommodate itself to inequalities.

Having now particularly described my invention, what I claim, and desireto secure by Letters Patent, is-

1. In an electrical signal device for railways, the combination with thegrounded rail, of a double conductor arranged in sections', each thelength of a block, a source of electricity for each block connected toone conductor at its forward end, a connection between the rear end ofthe same conductor with the front of the succeeding conductor on theopposite side, contacts on the locomotive engaging with said conductors,a circuit connected with the said contact embracing a magnet,abrake-controlling device actuated thereby, and a connection between oneof the contacts and the grounded rail, substantially as and for thepurposes specified.

2. In an electrical signal device for railways, the combination with thegrounded rail, of a double conductor arranged in sections, each thelength of a block, ya source of electricity for each block connected toone conductor at its forward end, a connection between the rear end ofthe same conductor with the front of the succeeding conductor on theopposite side, contacts ou the locomotive engaging with said conductors,a circuit connected with the said contact embracing a magnet, an armature-lever actuated thereby, and a pilot-valve thereon, the saidpilot-valve being connected with and actuating the air-relief valve ofthe brake system, substantially as and for the purposes specified.

3. In an electrical signal device for railways, the combination with thegrounded rail, of a double conductor arranged in sections, each thelength of a block, a source of electricity for each block connected toone conductor at its forward end, a connection between the rear end ofthe same conductor with the front of the succeeding conductor on theopposite side, contacts on the locomotive engaging with said conductors,a circuit connected with the said contact embracinga magnet, auarmaturelever actuated thereby, a switch, and a pilot-valve thereon, thesaid pilot-valve being connected with and actuating the air-relief valveof the brake system, substantially as and for the purposesspecifled.

4. In an electrical signal device for railways, a relief-valve for thebrakes of a train, consisting of a main valve, a balanced pilot-v valveconnected thereto, and electrical connections for actuating saidpilot-valve, substantially as and for the purposes speciied.

5. In an electrical signal device for railways, the combination with agrounded rail, of a circuit, a magnet therein, an armaturelever actuatedthereby, a balanced pilotvalve connected with said lever, arelief-valve, and connections between the two valves, substantially asand for the purposes specified.

6. In an electrical signal device for railways, a relief-valve for thebrakes of a train, consisting of a main relief-valve communi- ICO eatingwith thetrain-pipe, a piston thereon, This specification signed andwitnessed this a balanced pilot-valve, ports connecting said 6th dey ofMarch, 1902. pilot-Valve with the relief-Valve, a port con- EARL I,JESSOP meeting said pilot-valve with the train-pipe,

and a magnetic Connection for operating the 'Vinesses:

said pilot-valve, substantially as and for the CLARENCE A. HAMMETT,purposes specified. WILLIAM H. WALCOTT.

